SHOWS MANA REQUERIMENTS TO CAST A SPELL.
This snippet shows the mana (or blood, if vampire) needed for a player
to cast a spell with success.
You can type 'mana all' (or 'blood all') and you will see a list of all the spells
you can cast (if you have the minim level required and if you have practiced
it) followed by the amount of mana you need to cast it. If you have set ANSI
to ON, the spells that you can cast (because you have the enough mana) will be
yellow coloured, and the one you cannot will be red.
Also it is possible to type: mana <spell_name> , and it shows you the mana
required to this specific spell to be cast.

In MUD.H:
-Add this two defines:
#define MANA UMAX(skill->min_mana,100/(2+ch->level-skill->skill_level[ch->class])) 
#define BLOOD UMAX(1,(MANA+4)/8)

-Look for similar declarations and add:
DECLARE_DO_FUN( do_mana        );

In TABLES.C:
-Look for similar sentences of other commands and add:
 if ( !str_cmp( name, "do_mana" ))		return do_mana;

 if ( skill == do_mana  )		return "do_mana";

In ACT_INFO.C:
Cut and paste all this, (i.e. just before 'void do_slist...'

/***************************************************************************
*     Shows mana and blood (if vampire) requirements to cast a spell.      *
*          Created by Desden, el Chaman Tibetano - Jun 1999                *
* Snippets page: http://luisso.net/smaug_snippets.htm *
*                Email: jose@luisso.net                          *
***************************************************************************/
void do_mana( CHAR_DATA *ch, char *argument)
{
SKILLTYPE *skill=NULL;
char arg1[MAX_INPUT_LENGTH];
int sn;
int col = 0;

argument=one_argument(argument, arg1);

if (IS_NPC(ch))
   {
   send_to_char("Mobs cannot use this command.\n\r", ch);
  return;
    }

if (ch->class==CLASS_WARRIOR)
 {
 send_to_char("Warriors don't use mana to cast.\n\r",ch);
 return;
 }

if (arg1[0]=='\0')
 {
  if(IS_VAMPIRE(ch))
  send_to_char("Syntax: blood all\n\r        blood <spell>\n\r",ch);
  else
  send_to_char("Syntax: mana all\n\r        mana <spell>\n\r",ch);
  return;
 }

if(!strcmp(arg1,"all"))
 {
  set_pager_color(AT_YELLOW,ch); 
 
 if(IS_VAMPIRE(ch))
 send_to_pager("                         BLOOD REQUIRED TO CAST\n\r", ch);
 else
 send_to_pager("                         MANA REQUIRED TO CAST\n\r", ch);

 send_to_pager("                        -----------------------\n\r", ch);
  
for ( sn = 0; sn < top_sn ; sn++ )   
       	{
 	  skill=get_skilltype(sn);  
          if(ch->pcdata->learned[sn] < 1 ||
           !skill->name || !skill->min_mana )
         continue;

      if(ch->level>=skill->skill_level[ch->class]  )
       {
          if(IS_VAMPIRE(ch))
           {	
            if(ch->pcdata->condition[COND_BLOODTHIRST] >= BLOOD)
        	pager_printf_color(ch, "&Y%-12.12s:%4d   ",
                  skill->name, BLOOD);
            else
	     pager_printf_color(ch, "&R%-12.12s:%4d   ",
                skill->name, BLOOD);
           }
       else
           {
          if(ch->mana >= MANA)
        	pager_printf_color(ch, "&Y%-12.12s:%4d   ",
                  skill->name, MANA );
           else
	     pager_printf_color(ch, "&R%-12.12s:%4d   ",
                skill->name, MANA );
           }	    
           
          if(++col % 4 == 0)
            
          pager_printf(ch,"\n\r");
         
        }
     }

         pager_printf(ch,"\n\r");
   }

   else   

   {
    if((sn =skill_lookup( arg1)) > 0)
     { 
     skill=get_skilltype(sn);
     
     if(!skill->min_mana)
     {
      ch_printf(ch, "%s, '%s' doesn't use %s points.\n\r", ch->name, skill->name, IS_VAMPIRE(ch)?"blood":"mana");
    return;
     }
     
 if(ch->pcdata->learned[sn] < 1)
       {
         if (  ch->level < skill->skill_level[ch->class]  )
         {
         send_to_char( "You have not enough level to cast it.\n\r", ch );
         return;
         }
       else
        {
       send_to_char("You must practice a spell before using it.\n\r",ch);
       return;
       }   
      }

  pager_printf(ch,"You need %d %s points to cast '%s' with success.\n\r",IS_VAMPIRE(ch)?BLOOD:MANA,IS_VAMPIRE(ch)?"blood":"mana", skill->name);
    }
else
    ch_printf(ch, "That is not a spell or a skill.\n\r");
   }
return;
}

In ../SYSTEM/COMMANDS.DAT:
Add this two new commands:
#COMMAND
Name        blood~
Code        do_mana 
Position    100
Level       1  
Log         0
End

#COMMAND
Name        mana~
Code        do_mana 
Position    100
Level       1  
Log         0
End

Now, you must do a 'make clean' and a 'make', and thatīs all.

Please if you try it send me a mail telling me if you like it, errors, or any
comments you want. I'll thank you if mail me telling you are using this code. Thanks ;)
Desden el Chaman Tibetano - Jun 1999
Email: jose@luisso.net